Question: In 21 years, Ashley will be 4 times as old as she is right now. How old is she right now?
Explanation: We can use the given information to write down an equation about Ashley's age. Let Ashley's age be $a$ In 21 years, she will be $a + 21$ years old. At that time, she will also be $4 a$ years old. Writing this information as an equation, we get: $a + 21 = 4 a$ Solving for $a$ , we get: $3 a = 21$ $a = 7$.